Governments worldwide have provided $200 billion in financial aid to airlines, but as much as $80 billion more will be needed this year, according to Iata.

Alexandre de Juniac, Iata director general, said: “Government relief packages have been vital.” But he warned: “Airlines remain in a struggle for survival.”

Iata estimates governments have so far stumped up $200 billion in various forms of aid, including loans and credit guarantees. But de Juniac said: “Even this staggering amount will not be enough if travel restrictions persist well into 2021. More will be needed.

“The proliferation of travel restrictions we have seen since the start of the year makes our call for government aid even more important.

“If governments inject $70 billion to $80 billion in 2021 it would help to bridge the gap.”

He said the aid would need to be “without too much debt instruments because the industry is too heavily dependent on debt already”.

However, de Juniac argued: “There will be a turning point in this crisis and it’s important to be prepared for it.

“I don’t think anyone foresees a world free from Covid-19 anytime soon, certainly not in the next months or even this year. But our ability to manage the risk is increasing as more people are vaccinated and testing capacity expands.

“Eventually, we will be at a point where these and other measures give governments reassurance the risk of re-starting travel is tolerable.”

He said: “We are eager to work with governments to understand what the benchmarks and conditions will be to give people back freedom of movement.”

De Juniac suggested carriers would be able to restore 50%-60% of their capacity quickly, but a fuller return would take up to 18 months.

He said: “The industry is probably ready to come back pretty quickly to 50% of capacity, and probably to 60%.

“After that it will take some months to rehire [staff] and update the licences of pilots and cabin crew. To come back to full capacity could take one to one-and-a-half years.”